The US presidential candidates have been arguing about it. The American media talk constantly about it.
And the opinion polls have been asking voters about it.

Bush risks alienating his natural constituency

But just how much will the war in Iraq affect the November elections? Hugh Sykes found evidence that, with mounting US casualties, the answer could be "quite a lot".

Bill Clinton reputedly had a note by his desk during his first presidential election campaign that simply said: "It's the economy, stupid!"

President Bush should have one that reads: "It's Iraq, stupid!"

Almost everyone I've spoken to here in over two weeks mentions Iraq as the number one election issue, and the most frequent question I've heard is: What has Iraq to do with the 11 September 2001 attacks?

There is widespread - and, I sense, slowly growing - mystification about the Iraq war of George Bush and Tony Blair.

A cartoon in the Fayetteville Observer in North Carolina shows a car carrying the Bush Re-Election Bandwagon, complete with trombones and tuba blaring out of the rear windows.

Mounting costs

But the car is held up at a railroad crossing - the train passing by is carrying a military tank marked "Iraq".

We can't trust the president any more

Army wife Jessie Bigby

People are asking more and more: was it worth it? The question is about economics and about the human cost.

The war and its aftermath is costing billions of dollars to a nation with huge trade and budget deficits.

And it's costing lives.

The American death toll is clocking steadily up towards 1,000 and the number of seriously injured is about 7,000 - a figure scarcely reported here.

That cartoon appearing in a newspaper in Fayetteville is significant. Fayetteville is the small, heartland American town alongside Fort Bragg, the largest military base on this continent.

It has the usual strip of shopping malls, fast-food restaurants and petrol stations. But there is a "historic" district - small homes and shops in tree-lined streets.

Among them there's an independent cinema called the Cameo. It's run by Chris and Nazim Kuenzel.

Nazim is an Iranian-American who came here when she was 12 years old.

Standing ovations

They braved some expected local wrath recently and put on Michael Moore's anti-Bush, anti-Iraq war polemic, Fahrenheit 9/11.

The anti-war film Fahrenheit 9/11 has divided Americans

There was hardly any wrath. The film was so popular, they had to put on extra shows every night at midnight.

All the shows were sold out and, at 14 out of 15 performances during the first week, there were standing ovations at the end, from audiences that were 80% soldiers and their partners.

(Chris and Nazim knew that because they give military discounts to customers with army ID cards.)

One army wife, Jessie Bigby, summed up her unease when she told me:

"There was an attack on America on 9/11. We knew who did it. We went after him.

"But then we lost our focus and went after Saddam Hussein who had nothing to do with it. And they tried to tell us that he did.

"And we know that he didn't. So now we can't trust the president any more."

Jessie's husband Mike has already spent a year in Iraq. Now he's going back there, for 18 months.

She told me she has "a bad feeling about it".

Casualties

Further north in Pennsylvania - a so-called swing state, where candidates are desperate to woo undecided voters - there's a deeply conservative institution: the First Troop Philadelphia City Cavalry.

We've started shooting at someone who was not shooting at us. It doesn't make sense

Republican party member Bill Buchanan

Bill Buchanan, a leading member and card-carrying Republican, sighed when he told me George W Bush would not be getting his vote this time.

The reason? Iraq.

Bill said: "To risk nearly 1,000 American lives and so many casualties, there has to be a pressing reason. There was not."

He went on: "When I joined the military, I was taught to shoot back at the guy shooting at me.

"His name was Osama Bin Laden. We've stopped shooting at him and started shooting at someone who was not shooting at us. It doesn't make sense."

Bill runs a bed-and-breakfast house in Philadelphia. One of his other guests, William Coleman, came down one morning and sat at the communal dining table wearing a Manchester United shirt.

He'd made a two-hour plane journey from New Orleans to see his beloved English soccer team play a summer friendly against Celtic.

He's one of those fans far away - an American who developed a passion for a team just from watching them on television.

Veteran's view

John Kerry's status as a war veteran appeals to some voters

William fought in the Vietnam War and he is another Republican who says there is no way he'll vote for George Bush this time.

He told me that, when he was brought up in the 1950s, he was always taught that Germany had been utterly wrong to start a pre-emptive war.

But now America has done exactly that, and has alienated most of its allies as a result.

William Coleman is a thoughtful, kind-faced man who speaks slowly and carefully, and he believes he speaks for many when he says:

"As commander-in-chief, the president has a responsibility not to use the military in an irresponsible manner.

"I think that in this case, in Iraq, George W Bush has subjected the military to unnecessary danger."

William Coleman, like several of the uneasy Republicans I met, told me he will grit his teeth and vote for that other Vietnam War veteran, John Kerry.

From Our Own Correspondent was broadcast on Saturday, 14 August, 2004 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.